[llvm] r255220 - [WebAssembly] Implement mixed-type ISD::FCOPYSIGN.

[Dan Gohman via llvm-commits]

Author: djg
Date: Wed Dec  9 22:55:31 2015
New Revision: 255220

URL: http://llvm.org/viewvc/llvm-project?rev=255220&view=rev
Log:
[WebAssembly] Implement mixed-type ISD::FCOPYSIGN.

ISD::FCOPYSIGN permits its operands to have differing types, and DAGCombiner
uses this. Add some def : Pat rules to expand this out into an explicit
conversion and a normal copysign operation.

Added:
    llvm/trunk/test/CodeGen/WebAssembly/copysign-casts.ll
Modified:
    llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrFloat.td
    llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrInfo.td

Modified: llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrFloat.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrFloat.td?rev=255220&r1=255219&r2=255220&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrFloat.td (original)
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrFloat.td Wed Dec  9 22:55:31 2015
@@ -38,6 +38,12 @@ defm NEAREST : UnaryFP<fnearbyint, "near
 
 } // Defs = [ARGUMENTS]
 
+// DAGCombine oddly folds casts into the rhs of copysign. Unfold them.
+def : Pat<(fcopysign F64:$lhs, F32:$rhs),
+          (COPYSIGN_F64 F64:$lhs, (F64_PROMOTE_F32 F32:$rhs))>;
+def : Pat<(fcopysign F32:$lhs, F64:$rhs),
+          (COPYSIGN_F32 F32:$lhs, (F32_DEMOTE_F64 F64:$rhs))>;
+
 // WebAssembly doesn't expose inexact exceptions, so map frint to fnearbyint.
 def : Pat<(frint f32:$src), (NEAREST_F32 f32:$src)>;
 def : Pat<(frint f64:$src), (NEAREST_F64 f64:$src)>;

Modified: llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrInfo.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrInfo.td?rev=255220&r1=255219&r2=255220&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrInfo.td (original)
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyInstrInfo.td Wed Dec  9 22:55:31 2015
@@ -154,7 +154,7 @@ include "WebAssemblyInstrMemory.td"
 include "WebAssemblyInstrCall.td"
 include "WebAssemblyInstrControl.td"
 include "WebAssemblyInstrInteger.td"
-include "WebAssemblyInstrFloat.td"
 include "WebAssemblyInstrConv.td"
+include "WebAssemblyInstrFloat.td"
 include "WebAssemblyInstrAtomics.td"
 include "WebAssemblyInstrSIMD.td"

Added: llvm/trunk/test/CodeGen/WebAssembly/copysign-casts.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/WebAssembly/copysign-casts.ll?rev=255220&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/WebAssembly/copysign-casts.ll (added)
+++ llvm/trunk/test/CodeGen/WebAssembly/copysign-casts.ll Wed Dec  9 22:55:31 2015
@@ -0,0 +1,28 @@
+; RUN: llc < %s -asm-verbose=false | FileCheck %s
+
+; DAGCombiner oddly folds casts into the rhs of copysign. Test that they get
+; unfolded.
+
+target datalayout = "e-p:32:32-i64:64-n32:64-S128"
+target triple = "wasm32-unknown-unknown"
+
+declare double @copysign(double, double) nounwind readnone
+declare float @copysignf(float, float) nounwind readnone
+
+; CHECK-LABEL: fold_promote:
+; CHECK: f64.promote/f32 $push0=, $1
+; CHECK: f64.copysign    $push1=, $0, $pop0
+define double @fold_promote(double %a, float %b) {
+  %c = fpext float %b to double
+  %t = call double @copysign(double %a, double %c)
+  ret double %t
+}
+
+; CHECK-LABEL: fold_demote:
+; CHECK: f32.demote/f64  $push0=, $1
+; CHECK: f32.copysign    $push1=, $0, $pop0
+define float @fold_demote(float %a, double %b) {
+  %c = fptrunc double %b to float
+  %t = call float @copysignf(float %a, float %c)
+  ret float %t
+}